MB-PBA: Leveraging Merkle Tree and Blockchain to Enhance User Profile-based Authentication in E-Learning Systems

User authentication in online systems is always a big challenge in determining whether the logged-in user is the legitimate account owner. This challenge becomes critical in E-learning systems since it affects the assessment result of learners accurately. User profile-based authentication (PBA) has shown its advantages compared with other existing approaches. The PBA system will generate random questions and then evaluate the users' answers based on the collected information when the user registered into the system. However, this approach may reveal the users' data when the system is compromised and exploited. In this paper, we utilize the dominant features of the Merkle tree data structure and smart contracts on Blockchain to improve the PBA approach. The proposed method simplifies identity authentication, protects user confidential information, and enhances the security factor in terms of data integrity, user information transparency, and system availability. Our preliminary experiments have shown the potential and feasibility of the proposed authentication method.